Margie ....
The same is true in my garden, but my temps dropped from the triple digits to low 90s. This week they are moving into the 80s for a few days. I am living in an area where we are in the third year of extreme drought, so even tho' I've watered, the roses look stressed.
Your rose should be fine, but I really don't know your climate, so I am just talking off the top of my head. You asked about the "why" of something and I felt comfortable passing along as much information that I could pull out of my tired brain today.
Bonica is a strong rose. The seed parent contains essentially three species roses. The pollen parent has a lot of modern roses mostly dating around the 1950s with a few older "modern roses". I doubt if it will go fully dormant, but I think your temps are warm enough for now not to set it back while it settles into its new location.
Do you have die back in your garden ?
Smiles,
Lyn
